77747986 has 4 divisors (see below), whose sum is σ = 116621982. Its totient is φ = 38873992.

The previous prime is 77747983. The next prime is 77748001. The reversal of 77747986 is 68974777.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68974777 = 1409 ⋅48953.

It can be written as a sum of positive squares in only one way, i.e., 77528025 + 219961 = 8805^2 + 469^2 .

It is not an unprimeable number, because it can be changed into a prime (77747983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19436995 + ... + 19436998.

Almost surely, 2^77747986 is an apocalyptic number.

77747986 is a deficient number, since it is larger than the sum of its proper divisors (38873996).

77747986 is a wasteful number, since it uses less digits than its factorization.

77747986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38873995.

The product of its digits is 4148928, while the sum is 55.

The square root of 77747986 is about 8817.4818400720. The cubic root of 77747986 is about 426.8052136596.

The spelling of 77747986 in words is "seventy-seven million, seven hundred forty-seven thousand, nine hundred eighty-six".